隧道锚洞室开挖中围岩变形规律数值模拟及监测分析

摘要

隧道锚施工工序繁琐、围岩扰动交互作用明显，力学行为复杂。以岱山大桥隧道锚碇施工为工程原型，采用数值模拟结合实测数据对隧道锚施工期间围岩变形进行了深入分析。研究发现：上台阶开挖对围岩扰动最大，并伴有较大变形速率，但后行洞开挖对先行洞围岩的变形影响较小；小净距隧道锚室采取两侧洞身开挖面错开一定距离进行，可有效减少相互影响，并根据实测数据揭示了锚室围岩变形规律及发展模式，为同类工程的施工和设计提供了有益的参考。%Complex construction process of tunnel anchorage and the interaction of surrounding rock disturbance would lead to the complicated mechanical behavior.Taking the tunnel anchorage construction of Daishan Bridge as an engineering pro-totype,numerical simulation combined with the measured data was used to analyze the variation laws of surrounding rock during the construction.The study results showed that:The disturbance during upper bench cutting had the greatest impact on the surrounding rock’s deformation and with large deformation rate,but the construction of the following tunnel had less effect on the existing tunnel.By adjusting the stagger distance of both sides of the excavation surface,the surrounding rock’s deformation and the comparison of the simulation result could be better controlled,and the development model and deformation laws of surrounding rock could be revealed based on the monitoring data.It could provide a reference for the construction and design of the similar engineering.